JP2011201339A - Vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle which uses an elastic force saved in an elastic body as a driving force, secures a capability for smoothly changing a proceeding direction with a few components, and can save energy with a small size and light weight.SOLUTION: The vehicle body 20 is equipped with a pair of main driving wheels 53A, 53B that are independently driven. The vehicle body 20 can be steered by the difference in rotation speeds between the pair of main driving wheels 53A, 53B. The vehicle includes: an energy saving mechanism 60 including the elastic body capable of outputting the saved elastic force as the power while changing the input power into the elastic force to save; and an auxiliary driving wheel 61 driven by the power of the energy saving mechanism 60. A rotating shaft line of the auxiliary driving wheel 61 exists on a vertical surface on which the pair of main driving wheels 53A, 53B rise from each ground contact point.

Description

  The present invention relates to a vehicle that travels with an elastic force stored in an elastic body.

  2. Description of the Related Art Conventionally, in a production site such as an automobile factory, for example, a battery is mounted as a vehicle that conveys parts (workpieces) such as an engine and a gear box, and a driving motor is driven by rotating a driving motor with electric power from this battery An automated guided vehicle (AGV) that travels by driving the vehicle is used. In this type of transport vehicle, since a heavy object such as an engine component is transported, a sufficient output is required for the traveling motor. Therefore, there is a concern about an increase in equipment cost and power consumption due to an increase in the size of the motor and the accompanying increase in size of the vehicle.

  Patent Document 1 describes a configuration in which an electric or hydraulic drive system is not provided as a transport vehicle for transporting parts (workpieces) such as an automatic transmission. In this transport vehicle, the rack and pinion mechanism is driven by the weight of the work to be transported to generate a forward driving force of the wheel, and the weight of the work is stored in a coil spring (elastic body) provided on the base. Then, the rack and pinion mechanism can be driven in the reverse direction by the repulsive force of the coil spring when the workpiece is removed from the pedestal, and the reverse drive force of the vehicle can be obtained.

Japanese Patent Application Laid-Open No. 2004-331052

  In order to reduce the equipment cost of the production line and save energy, when the production process is made common to a plurality of types of products having different models and specifications, it is desirable that the traveling direction of the transport vehicle can be changed. The described transport vehicle has a problem that it can only reciprocate on a predetermined straight line.

  The present invention has been made in view of the above-described circumstances, and uses the elastic force stored in the elastic body as a driving force, as well as ensuring performance capable of smoothly changing the traveling direction with a small number of components, and is compact and lightweight. An object of the present invention is to provide a vehicle that can save energy.

  In the present invention, the vehicle body includes a pair of independently driven drive wheels, the vehicle body is configured to be steerable with a difference in rotational speed between the pair of drive wheels, and the input power is converted into elastic force and stored, An energy storage mechanism including an elastic body that can output the stored elastic force as power, and an auxiliary drive wheel that is driven by the power of the energy storage mechanism, and the rotation axis of the auxiliary drive wheel is connected to each grounding portion of the pair of drive wheels It is characterized by being present in a vertical plane that rises from.

In the present invention, the vehicle main body includes a pair of independently driven drive wheels, and the vehicle main body is configured to be steerable by a difference in rotational speed between the pair of drive wheels. Therefore, only the rotational speed of the pair of drive wheels is controlled. The traveling direction of the vehicle body can be changed while moving forward or backward. Therefore, it is possible to perform steering as intended without providing a complicated steering mechanism and suppressing the number of parts.
In the present invention, since the rotation axis of the auxiliary driving wheel exists in a vertical plane rising from each grounding point of the pair of driving wheels, the auxiliary driving wheel can be provided without a complicated swing structure or the like. This prevents dragging and enables smooth steering.
Further, in the present invention, since the auxiliary drive wheel driven by the elastic force stored in the energy storage mechanism is provided, for example, the vehicle is stored in the energy storage mechanism at the start of a vehicle that requires a large driving force. By driving the auxiliary driving wheel with the elastic force, the force required for driving the main driving wheel can be reduced, and the motor and battery for driving the main driving wheel can be made small and light. Therefore, the vehicle becomes smaller and lighter, and power consumption can be suppressed.

  In addition, the present invention includes a pair of drive wheels that can be independently driven and rotated in the forward and reverse directions, and that the vehicle body can be steered by a rotational speed difference and / or forward and reverse rotation control of the pair of drive wheels. An energy storage mechanism including an elastic body capable of outputting the stored elastic force as power, and an auxiliary drive wheel driven by the power of the energy storage mechanism. The rotation axis of the drive wheel is present in a vertical plane rising from each grounding point of the pair of drive wheels.

In the present invention, the vehicle main body includes a pair of drive wheels that can be independently driven and rotated forward and backward, and the vehicle main body is configured to be steerable by rotational speed difference and / or forward / reverse rotation control of the pair of drive wheels. The traveling direction can be changed while moving forward or backward, and the traveling direction of the vehicle body can be changed on the spot without moving forward and backward. Therefore, it is possible not only to provide a complicated steering mechanism but also to reduce the number of components, and to perform steering as intended, and to perform steering in a narrow place.
In the present invention, since the rotation axis of the auxiliary driving wheel exists in a vertical plane that rises from each grounding point of the pair of driving wheels, the auxiliary driving wheel does not have a complicated swing structure or the like. Smooth drag is possible by preventing wheel drag.
Further, in the present invention, since the auxiliary drive wheel driven by the elastic force stored in the energy storage mechanism is provided, for example, the vehicle is stored in the energy storage mechanism at the start of a vehicle that requires a large driving force. By driving the auxiliary driving wheel with the elastic force, the force required for driving the main driving wheel can be reduced, and the motor and battery for driving the main driving wheel can be made small and light. Therefore, the vehicle becomes smaller and lighter, and power consumption can be suppressed.

Further, the present invention is characterized in that the vehicle body includes a plurality of casters so as to surround each drive wheel and auxiliary drive wheel.
In the present invention, since the vehicle main body includes a plurality of casters so as to surround each drive wheel and auxiliary drive wheel, the vehicle main body is stable even if the ground contact points of each drive wheel and auxiliary drive wheel are aligned. Can drive.

  The present invention also includes a vehicle body having a carriage, a drive unit coupled to the carriage so as to be relatively rotatable, and a turning brake capable of restraining the drive unit and the carriage so as not to be relatively rotatable. A pair of reverse-rotating drive wheels is provided, and the vehicle body can be steered by the rotational speed difference and / or forward / reverse rotation control of the pair of drive wheels, and the turning brake is released and one drive wheel is By rotating and reversely rotating the other drive wheel, the drive unit can be turned, and the input power is converted into elastic force and stored, while the elastic body that can output the stored elastic force as power Including an energy storage mechanism and an auxiliary drive wheel driven by the power of the energy storage mechanism, the auxiliary drive wheel is disposed in the drive unit, and the rotation axis of the auxiliary drive wheel is set up from each grounding point of the pair of drive wheels. Characterized in that the presence in a plane perpendicular to rise.

  In the present invention, the vehicle main body includes a carriage, a drive unit coupled to the carriage so as to be relatively rotatable, and a turning brake capable of restraining the drive unit and the carriage so as not to be relatively rotatable. Since the vehicle body is configured to be steerable by controlling the difference in rotational speed and / or forward / reverse rotation control of the pair of drive wheels, the traveling direction can be changed while moving forward or backward. The traveling direction of the vehicle body can be changed on the spot without moving forward and backward. Therefore, it is possible not only to provide a complicated steering mechanism but also to reduce the number of components, and to perform steering as intended, and to perform steering in a narrow place.

In the present invention, the turning brake is released, one drive wheel is rotated forward, and the other drive wheel is rotated reversely so that the drive unit can be turned. A rectangular wave or trapezoidal wave path can be traveled while being held.
Therefore, a complicated route can be taken even in a narrow place, and the layout flexibility of the production system is improved. Further, since the direction of the carriage is maintained during steering, no rotation moment is applied to the load, and the conveyance can be speeded up.

In the present invention, since the rotation axis of the auxiliary driving wheel exists in a vertical plane that rises from each grounding point of the pair of driving wheels, the auxiliary driving wheel does not have a complicated swing structure or the like. Smooth drag is possible by preventing wheel drag.
Further, in the present invention, since the auxiliary drive wheel driven by the elastic force stored in the energy storage mechanism is provided, for example, the vehicle is stored in the energy storage mechanism at the start of a vehicle that requires a large driving force. By driving the auxiliary driving wheel with the elastic force, the force required for driving the main driving wheel can be reduced, and the motor and battery for driving the main driving wheel can be made small and light. Therefore, the vehicle becomes smaller and lighter, and power consumption can be suppressed.

Further, the present invention is characterized in that the cart is provided with a plurality of casters.
In the present invention, since the carriage is provided with a plurality of casters, the vehicle body can travel stably even if the ground contact points of the drive wheels and the auxiliary drive wheels are aligned.

According to the present invention, since the rotation center axis of the auxiliary driving wheel exists on a vertical surface rising from each grounding point of the pair of driving wheels, the auxiliary driving wheel can be driven without a complicated swinging structure or the like. Wheel drag can be prevented and smooth steering is possible.
Further, according to the present invention, since the auxiliary drive wheel driven by the elastic force stored in the energy storage mechanism is provided, by driving the auxiliary drive wheel with the elastic force stored in the energy storage mechanism, The force required to drive the main drive wheel can be reduced, and the motor and battery for driving the main drive wheel are small and light. Therefore, power consumption can be suppressed by reducing the size and weight of the vehicle.

In addition, according to the present invention, since the pair of main drive wheels are driven independently, the vehicle can be steered only by making a difference in the rotation speeds of the pair of main drive wheels. It is possible to change the traveling direction of the vehicle body while moving forward or backward simply by controlling. Therefore, it is possible to perform steering as intended without providing a complicated steering mechanism and suppressing the number of parts.
Further, according to the present invention, since the pair of main drive wheels can rotate forward and backward, it is possible to change the direction of the vehicle body on the spot without moving forward and backward. Therefore, steering in a narrow place is possible.

According to the present invention, the vehicle body includes a carriage, a drive unit coupled to the carriage so as to be relatively rotatable, and a turning brake capable of restraining the drive unit and the carriage so as not to be relatively rotatable, and the drive unit is independently driven. And a pair of drive wheels that can rotate forward and reverse, and the drive unit can be turned by releasing the turning brake, rotating one drive wheel forward, and rotating the other drive wheel backward. The vehicle can travel along a rectangular or trapezoidal path while maintaining the direction of the carriage.
Therefore, a complicated route can be taken even in a narrow place, and the layout flexibility of the production system is improved. Further, since the direction of the carriage is maintained during steering, no rotation moment is applied to the load, and the conveyance can be speeded up.
Further, according to the present invention, since the carriage is provided with a plurality of casters, the vehicle main body can travel stably even if the ground contact portions of the drive wheels and the auxiliary drive wheels are aligned.

It is a top view which shows the production system to which the conveyance vehicle which concerns on this embodiment is applied. In the production system shown in FIG. 1, it is an enlarged plan view of a portion where the transport vehicle takes a rectangular wave path. It is a partial omission side view of the conveyance vehicle which is an example of application of the vehicle concerning this embodiment. It is a partially omitted plan view of a transport vehicle that is an application example of a vehicle according to the present embodiment. (A) is a partially omitted side view of the main part of the drive unit, and (b) is a partially omitted plan view. It is a top view which shows typically the direction of each drive wheel at the time of steering, and each locus. (A)-(e) is a top view which shows typically vehicle body operation | movement at the time of traversing using a contact body. (A) is a partially omitted side view showing the operation of the vehicle body when the main drive wheel is rotated forward and backward, and (b) is a partially omitted plan view. In the production system shown in FIG. 1, it is an enlarged plan view of a portion where the transport vehicle takes a trapezoidal wave path. (A)-(e) is a top view which shows typically the vehicle main body operation | movement at the time of skewing using a contact body. It is a partially-omission side view of the conveyance vehicle which concerns on another embodiment. It is a principal part enlarged plan view of the conveyance system in which a contact body is not installed. (A)-(f) is a top view which shows typically the vehicle main body operation | movement at the time of traversing without using a contact body.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
1 and 2 show a system that includes a production line at a production site such as an automobile factory and performs production by so-called flow work.
This production line has a first line 100 and a second line 200 arranged in parallel. The first line 100 and the second line 200 merge at the inlet and the outlet, and the third line Connected to line 300. A plurality of work stations S are provided in the first line 100 and the second line 200, and work robots are arranged in the plurality of work stations S, respectively. The first line 100 and the second line 200 are production lines for different products, but the work station S1 is shared. The second line 200 is formed with a recessed line 200 </ b> A that merges with the first line 100.
This production line is provided with a plurality of transport vehicles (vehicles) 10 that can load workpieces W and can sequentially move each work station S.

FIG. 3 is a partially omitted side view of the transport vehicle 10, and FIG. 4 is a plan view thereof. In the following description, descriptions of directions such as front and rear, right and left, and up and down are for the vehicle body. In the figure, an arrow FR indicates the front of the vehicle body, an arrow R indicates the right side of the vehicle body, and an arrow UP indicates the upper side of the vehicle body.
The transport vehicle 10 is an electric vehicle that can travel on a desired route with a driving force from a main power unit 45 mainly using a battery 57 (power supply unit) as a power source. In the production line shown in FIG. This is an AGV that loads (work W) on the mounting table 31 and conveys it to a desired position in the factory. In the present embodiment, the transport vehicle 10 will be described as an example of the electric vehicle. However, the present invention is applicable to any vehicle that travels electrically, such as a passenger car, an electric cart, and a train.

  The transport vehicle 10 includes a vehicle body 20, and the vehicle body 20 includes a carriage 21 and a drive unit 23 connected to the carriage 21. Legs 21B are formed on the carriage frame 21A of the carriage 21, and casters 25 are supported on the legs 21B so as to be pivotable in four directions. The carriage frame 21A is provided with a loading unit 30 on which the workpiece W is loaded. The loading unit 30 is a table 31 on which a work W is placed, and can be lifted up and down in the vertical direction so that the stage 31 and the work W can be held at a desired height position. Device 33. The elevating device 33 includes a hydraulic cylinder (elevating mechanism) 37 that elevates and lowers the mounting table 31 via a rod 35 fixed to a substantially lower surface of the mounting table 31, and a hydraulic circuit (not shown) that drives the hydraulic cylinder 37. It is composed of The raising / lowering operation of the mounting table 31 is fixed to the rail 38 extending in the vertical direction of the vehicle body parallel to the rod 35 on both sides in the vehicle width direction of the vertical plate 31A provided at the rear of the mounting table 31, and to the carriage frame 21A side. 38 is guided by a guide recess 39 which is slidably engaged.

  Although not shown, the hydraulic circuit is connected to an upper chamber and a lower chamber of a hydraulic cylinder 37 defined by a piston coupled to the rod 35 via a control valve mechanism. The control valve mechanism is a valve device that can appropriately switch the communication state between the upper chamber and the lower chamber of the hydraulic circuit and the flow direction of the hydraulic oil, and is driven and controlled by the control unit 49 (see FIG. 3). In the middle of the hydraulic circuit, a pump that pressurizes and flows the hydraulic oil in the circuit and a generator (generator) that generates electric power by receiving the pressure and flow of the hydraulic oil are disposed. The electric power generated by the generator is stored in a battery 57 described later. A sensor 40 that detects a route on which the transport vehicle 10 should travel is provided on the bottom side of the carriage 21. The sensor 40 is, for example, a magnetic sensor, detects a magnetic field of a magnetic tape stuck on a route on which the transport vehicle 10 should travel in a factory, and outputs a signal to the control unit 49 (see FIG. 3). The outer periphery of the carriage 21 is covered with a body panel (not shown). In addition, a microwave receiving device (not shown) or a solar cell (not shown) is mounted on the body panel covering the outer periphery of the carriage 21, and from a microwave transmitting device (not shown) in the factory or illumination (not shown) ) May be received as microwaves or light, converted into electric power by a microwave receiver or a solar cell, and stored in the battery 57 as electric power.

The carriage 21 and the drive unit 23 are coupled to each other by a turning shaft 41 provided on the drive unit 23 and a bearing 42 provided on the carriage 21 so as to be relatively rotatable. The carriage 21 is provided with a turning brake 43 capable of restricting the rotation of the turning shaft 41. By operating the turning brake 43, the relative rotation between the drive unit 23 and the carriage 21 is restricted and integrated. It is possible.
In the present specification, hereinafter, the drive unit 23 is rotated relative to the carriage 21 around the turning shaft 41, and the direction of the drive unit 23 and the direction of the carriage 21 are changed relatively in a top view of the vehicle body 20. The operation is defined as turning, and the operation for changing the direction of main drive wheels 53A and 53B, which will be described later, in the top view of the vehicle main body 20 is defined as steering.

  As shown in FIG. 3, the drive unit 23 is driven mainly when the vehicle 10 is started during normal travel, for example, when the carrier vehicle 10 is started from a stopped state, and assists the travel by the main power unit 45 (assist The auxiliary power unit 47, the main power unit 45, the control unit 49 for comprehensively controlling the operation of the auxiliary power unit 47, the loading unit 30, and the like, and the main power unit 45, the auxiliary power unit 47, and the control unit 49 And a drive unit frame 50 mounted integrally.

As shown in FIG. 4, the main power unit 45 is driven independently by the control unit 49, and rotates to a pair of travel motors 51 </ b> A and 51 </ b> B capable of adjusting the rotation speed and rotating in the forward and reverse directions, and the drive unit frame 50. A pair of main drive wheels 53A and 53B that are pivotally supported and rotated based on the rotation of the pair of traveling motors 51A and 51B, and an encoder that measures the rotation angle around the drive shaft of the main drive wheels 53A and 53B 55A and 55B, and a battery 57 that supplies electric power to the traveling motors 51A and 51B.
The battery 57 is charged by an external power source (not shown) installed in the work station S when the transport vehicle 10 stops at a predetermined work station S for standby or work, for example. The transport vehicle 10 and the external power source can be easily electrically connected by, for example, a pair of male and female connectors that can be attached and detached by magnetic force.

  As shown in FIGS. 5 a and 5 b, the auxiliary power unit 47 can store power by converting the power into elastic force, while the energy storage mechanism 60 that can output the stored elastic force as power and the auxiliary power unit 47. An auxiliary drive wheel (drive wheel) 61 that is pivotally supported by the frame 65 and driven by the elastic force stored in the energy storage mechanism 60, and the drive shaft 67 of the energy storage mechanism 60 and the auxiliary drive wheel 61 are coupled or A clutch mechanism 63 that separates and a frame body 65 that covers each of the mechanisms are provided. The energy storage mechanism 60 mainly includes a winding shaft 60A, a winding shaft 60B, and a winding shaft in a state where one end is fixed to the winding shaft 60A and the other end is fixed to the winding shaft 60B and no elastic force is accumulated. And a mainspring spring 60C having a winding rod wound on the 60B side. When the mainspring 60C is wound around the hoisting shaft 60A by rotating the hoisting shaft 60A with an external force, an elastic force is applied to the mainspring spring 60C. Is stored, and when the external force is lost, the winding shaft 60B rotates based on the elastic force of the mainspring spring 60C. 60D is a bearing.

The winding shaft 60 </ b> B is rotatably supported by a bearing 60 </ b> D fixed to the frame body 65. The hoisting shaft 60A is rotatably supported by a bearing 60E fixed to the frame body 65 in the same manner as the take-up shaft 60B, but both ends of the hoisting shaft 60A extend outside the frame body 65. Yes. One extension portion is provided with a mainspring brake 60F for stopping the rotation of the shaft on the outer periphery of the shaft, and the outer shaft end portion is fitted with external equipment (not shown) to transmit external force, for example, a square cross section. It has become. The other extending portion is connected to a counter 60G that measures the number of windings.
The mainspring brake 60F is, for example, an electromagnetic brake, and allows or prohibits the rotation of the hoisting shaft 60A under the control of the control unit 49. Further, the mainspring brake 60F can adjust the amount of rotation of the hoisting shaft 60A, and the elastic force stored in the mainspring spring 60C of the energy storage mechanism 60 can be continuously or stepwise in the range of 0% to 100%. Output as power. According to this, since the elastic force stored in the mainspring spring 60C is not output at a stretch and the output amount can be controlled, the acceleration and speed of the transport vehicle 10 can be controlled appropriately.
Further, the counter 60G can adjust the number of windings according to the moving distance and the loaded weight.

A drive sprocket 60H is fixed at substantially the center of the hoisting shaft 60A coaxially with the hoisting shaft 60A. A bottomed cylindrical casing 60I is fixed to both sides of the drive sprocket 60H on the hoisting shaft 60A, and the mainspring spring 60C wound up in the casing 60I can be accommodated. One end of the mainspring spring 60C is coupled to the inner wall surface of the casing 60I, and the other end is coupled to the winding shaft 60B.
The drive sprocket 60H is connected to a driven sprocket 60K disposed coaxially with the drive shaft 67 by a chain 60J. The driven sprocket 60K is coupled to the drive shaft 67 via the clutch mechanism 63 so as to be connectable and detachable. The drive shaft 67 is coupled to the auxiliary drive wheel 61.

In the present embodiment, as shown in FIGS. 5a and 5b, the auxiliary drive wheel 61 has a vertical surface whose rotation axis L rises from the ground contact points SA and SB of the pair of main drive wheels 53A and 53B described above. It is arranged at a position existing in M. That is, the ground contact points SA and SB of the pair of main drive wheels 53A and 53B are in the same straight line as the ground contact point SC of the auxiliary drive wheel 61.
The control unit 49 controls the rotation of the traveling motors 51A and 51B for driving the main drive wheels 53A and 53B, and the turning brake 43 based on the rotation angles of the main drive wheels 53A and 53B measured by the encoders 55A and 55B. Turn on / off. Further, the mainspring brake 60F and the clutch mechanism 63 in the auxiliary power unit 47 are controlled, and the hydraulic pump and hydraulic circuit (not shown) of the loading unit 30 are controlled.

Next, the traveling operation of the vehicle will be described.
(When using the first line 100 and the third line 300 in FIG. 1)
The transport vehicle 10 basically travels (starts) using the auxiliary power unit 47 when starting from a stopped state under the control of the control unit 49, and travels using the main power unit 45 during normal travel after starting. Control is performed. For example, when the transport vehicle 10 is stopped at the standby station or the work station S, the battery 57 of the transport vehicle 10 is charged by an external power source provided at the standby station or the work station S. Further, the mainspring spring 60C of the energy storage mechanism 60 is wound around the hoisting shaft 60A by external power provided in the standby station or the work station S, and an elastic force is stored in the mainspring spring 60C.
At this time, the control unit 49 turns the clutch mechanism 63 in the disengaged state (off) when the hoisting shaft 60A rotates, and turns the mainspring brake 60F in the activated state (on) when the winding is finished. That is, the auxiliary drive wheel 61 is prevented from rotating by the rotation of the hoisting shaft 60A when the hoisting shaft 60A rotates. Then, by operating the mainspring brake 60F, the hoisting shaft 60A is fixed so that the stored elastic force is not released.

Next, along with charging of the battery 57 by the external power source, preparation for starting (starting) running is performed after the storage of the elastic force in the energy storage mechanism 60 is completed. That is, the control unit 49 puts the clutch mechanism 63 in a connected state (ON). As a result, the driven sprocket 60K coupled with the hoisting shaft 60A and the chain 60J engages with the drive shaft 67, and the rotation of the hoisting shaft 60A is transmitted to the drive shaft 67. The auxiliary drive wheel 61 coupled to the drive shaft 67 is driven by the rotational force. At this time, the rotation stop of the hoisting shaft 60A by the mainspring brake 60F is continued.
When the mainspring brake 60F is released, the hoisting shaft 60A and the winding shaft 60B are rotated by the elastic force stored in the mainspring spring 60C. The rotational force of the hoisting shaft 60A is transmitted to the drive shaft 67 via the drive sprocket 60H, the chain 60J, the driven sprocket 60K, and the clutch mechanism 63, and the auxiliary drive wheel 61 integrated with the drive shaft 67 is rotated. Starts.

In such starting by the auxiliary power unit 47, at least until the elastic energy stored in the mainspring spring 60C is released, the hoisting shaft 60A rotates to apply rotational torque to the auxiliary driving wheel 61. .
After the elastic force stored in the mainspring spring 60C is released, the transporting vehicle 10 can travel a certain distance by the inertial force by disengaging the clutch mechanism 63. Accordingly, by considering the weight of the transport vehicle 10 including the weight of the work W to be transported, the characteristics of the mainspring spring 60C, the loss of each bearing portion, etc., for example, It is also possible to travel between the work stations S with only the elastic force stored in the mainspring spring 60C of the energy storage mechanism 60.
A clutch (not shown) is also disposed between the drive shafts of the traveling motors 51A and 51B and the main drive wheels 53A and 53B, and when the auxiliary power unit 47 starts such a clutch, It can also be kept in a disconnected state. Then, it is possible to reduce the load on the traveling motors 51A and 51B that are not used at the time of starting, and to effectively suppress the load from the traveling motors 51A and 51B from affecting the starting operation.
When the vehicle continues to travel after the start by the auxiliary power unit 47, the control unit 49 drives the main power unit 45 and drives the traveling motors 51A and 51B with electric power from the battery 57. Driving can be continued as a normal electric vehicle.

  As shown in FIG. 1, the first line 100 is a straight line. When the main power unit 45 is driven to travel on the first line 100, the rotational speeds of the traveling motors 51A and 51B are made to coincide with each other so that the rotational speeds of the pair of main drive wheels 53A and 53B are made identical. . Thereby, the conveyance vehicle 10 can go straight. On the other hand, curves are drawn at the inlet D and the outlet E of the first line 100. In this case, with respect to the traveling direction, the rotational speed of the right main drive wheel 53B is increased more than the rotational speed of the left main drive wheel 53A, and turns to the left with a difference in rotational speed.

In the present embodiment, as shown in FIG. 5a, the auxiliary drive wheel 61 has a rotation axis L in a vertical plane M rising from the ground contact points SA and SB of the pair of main drive wheels 53A and 53B. The ground contact points SA and SB of the pair of main drive wheels 53A and 53B are located on the same straight line as the ground contact point SC of the auxiliary drive wheel 61 as shown in FIG.
In the conventional structure, the ground contact point SC of the auxiliary drive wheel 61 does not line up on the straight line L1 with respect to the ground contact points SA and SB of the pair of main drive wheels 53A and 53B, as shown by the broken line in the figure. It is placed at each vertex of the triangle. In this case, even if the steering of the transport vehicle 10 advances and the ground contact points SA and SB of the pair of main drive wheels 53A and 53B reach the straight line L2, the ground contact point SC ′ of the auxiliary drive wheel 61 is Delay backwards as shown by the broken line. The auxiliary drive wheel 61 does not turn toward the tangent line of its own steering locus during the period from the ground contact point SC to the ground contact point SC ′, that is, during steering, and the auxiliary drive wheel 61 rotates about the axis of rotation F of the frictional force F with the ground. The direction component f2 is received and dragged.
On the other hand, in the present embodiment, the ground contact points SA and SB of the pair of main drive wheels 53A and 53B and the ground contact point SC of the auxiliary drive wheel 61 exist on the same straight line both on the straight line L1 and on the straight line L2. Therefore, the main drive wheels 53A and 53B and the auxiliary drive wheel 61 all move toward the tangent line of their own steering locus, and the frictional force that the auxiliary drive wheel 61 receives from the ground is a component in the rotational axis direction of the auxiliary drive wheel 61. Does not include f2. Therefore, even if the auxiliary drive wheel 61 does not have a complicated swing structure or the like, dragging of the auxiliary drive wheel 61 can be prevented, and smooth steering is possible.
In the present embodiment, since the pair of main drive wheels 53A and 53B are driven independently, the vehicle main body 20 can be moved forward or backward by simply controlling the rotational speed of the main drive wheels 53A and 53B. Can change the direction of travel. Therefore, it is possible to perform steering as intended without providing a complicated steering mechanism and suppressing the number of parts.

  In the present embodiment, the auxiliary drive wheel 61 can be driven by the elastic force stored by the mainspring spring 60C of the energy storage mechanism 60 to start from a stopped state. In this case, the mainspring spring 60 </ b> C is wound up by external power when the transport vehicle 10 stops and can be performed simultaneously with the charging of the battery 57, so that no time loss occurs. Furthermore, after the start by the auxiliary power unit 47, electric travel by the main power unit 45 can be performed in the same manner as a general electric vehicle, so that a desired route can be traveled by a desired distance.

In general, the amount of electric power (current amount) of the motor during low-speed rotation is larger than that during a predetermined high-speed rotation, and the driving torque required for starting from the time of stopping is much larger than during steady running. In other words, if it is attempted to start the transport vehicle 10 with the traveling motors 51A and 51B, the traveling motors 51A and 51B must rotate at a low speed and output high torque, and the power consumption thereof Since the main spring 60C is wound up, the amount is extremely large compared to the power consumption of external power.
On the other hand, in the conveyance vehicle 10, since the start can be covered by the elastic force of the mainspring spring 60C, low-power and small-sized motors can be used as the traveling motors 51A and 51B. In the transport vehicle 10 that also needs to transport W, the load related to starting is very large, and the effect is remarkable. Furthermore, since it is not necessary to use the battery 57 almost at the time of start in the transport vehicle 10, the capacity and size of the battery 57 can be reduced, and the transport vehicle 10 can be reduced in weight and power consumption. Moreover, since the mainspring spring 60C is used as the elastic body constituting the energy storage mechanism 60, the auxiliary power unit 47 can be configured easily and at low cost.

(When using the second line 200 and the third line 300 in FIG. 1)
In the present embodiment, in the traveling vehicle 10 that is traveling straight, the control unit 49 rotates the pair of main drive wheels 53A and 53B in the forward direction at the same rotational speed. In general, the turning brake 43 is turned on to restrain the drive unit 23 and the carriage 21 from turning.
At the time of steering, the control unit 49 rotates the pair of main drive wheels 53A and 53B at different rotational speeds while rotating forward. Due to this rotational speed difference, the trajectory of the pair of main drive wheels 53A, 53B draws an arc centered on the same point, and the direction of the drive unit 23 is changed as the transport vehicle 10 advances.
As shown in FIG. 1, the second line 200 is not a straight line but is provided with a recessed line 200 </ b> A. In the dent line 200A, the direction of the carriage 21 is made coincident with the traveling direction, the drive unit 23 is turned 90 °, and the drive unit 23 is driven to run while turning 90 °.
In the present specification, hereinafter, moving the vehicle body 20 in the lateral direction while maintaining the posture of the carriage 21 is defined as traversal.

In the present embodiment, for example, as shown in FIG. 2, four contact bodies (hereinafter referred to as guides) 81 are arranged at each corner of the dent line 200A. The guide 81 is fixed to the fixing portion and is parallel to the second line 200.
As shown in FIG. 7a, the carriage 10 travels in the direction of the arrow, and when the carriage 10 reaches the dent line 200A shown in FIG. 2, for example, the vehicle moves the guide 21 to the carriage 21 as shown in FIG. Stop by contacting the sides. Next, the control unit 49 releases the turning brake 43 and activates the pair of main drive wheels 53A and 53B to rotate forward and backward as shown in FIG. 7c. At this time, since the carriage 21 is restricted by the guide 81 so as not to turn, only the drive unit 23 rotates around the turning shaft 41 as shown in FIG. The rotation of the drive unit 23 is an operation (steering) for changing the direction of the pair of main drive wheels 53A and 53B, and an operation (turning) for relatively changing the direction of the drive unit 23 and the direction of the carriage 21. . When the drive unit 23 is driven in the state of FIG. 7d, as shown in FIG. 7e, traversing is started.
At this time, since the control unit 49 acquires the rotation angle measurement value around the drive shaft of the pair of main drive wheels 53A and 53B from the encoders 55A and 55B, the rotation angle (steering / turning angle) of the drive unit 23 is obtained. It can be specified as 90 °, and when the rotation angle of the drive unit 23 reaches 90 ° as shown in FIG.
The transport vehicle 10 repeats the above-described procedure in the dent line 200 </ b> A three times, and returns to the straight line portion of the second line 200.

In the present embodiment, as shown in FIGS. 8a and 8b, the pivot shaft 41 exists at the midpoint of the line segment connecting the ground contact points SA and SB of the pair of main drive wheels 53A and 53B. The trajectory of the main drive wheels 53A and 53B when the drive wheels 53A and 53B are rotated forward and backward is an arc having a diameter equal to the tread width W (distance between the pair of main drive wheels 53A and 53B) around the turning shaft 41. It becomes. Here, assuming that the rotation angle of the main drive wheels 53A and 53B is ω1, the rotation angle of the drive unit 23 is ω2, and the diameter D of the main drive wheels 53A and 53B, the following relational expression holds.
D ・ ω1 ＝ W ・ ω2
Therefore, the rotation angle (steering / turning angle) of the drive unit 23 can be specified by acquiring the rotation angle measurement values around the drive shafts of the main drive wheels 53A, 53B from the encoders 55A, 55B. When the rotation angle (steering / turning angle) of the drive unit 23 reaches 90 °, the control unit 49 stops the forward / reverse rotation of the pair of main drive wheels 53A and 55B. Thereby, only the drive unit 23 rotates and changes the direction of 90 ° while maintaining the posture of the carriage 21 from the beginning. Then, after turning the turning brake 43 and restraining the drive unit 23 and the carriage 21 so as not to turn, when the pair of drive wheels are rotated forward, the vehicle body 20 starts traversing while maintaining the position of the carriage 21. The

In the embodiment described above, the rotation angle (steering / turning angle) of the drive unit 23 is 90 °. However, the rotation angle may be any angle, for example, as shown in FIG. (Steering / turning angle) may be 45 °.
In the present specification, hereinafter, moving the vehicle body 20 in an oblique direction while maintaining the posture of the carriage 21 is defined as skew.
As shown in FIG. 10a, when the transport vehicle 10 travels in the direction of the arrow and the transport vehicle 10 reaches, for example, the dent line 200A shown in FIG. 9, the vehicle moves the guide 21 to the guide 21 as shown in FIG. Stop by contacting the sides. Next, the control unit 49 releases the turning brake 43 and activates the pair of main drive wheels 53A and 53B to rotate forward and backward as shown in FIG. 10c.
At this time, since the control unit 49 acquires the rotation angle measurement values around the drive shafts of the main drive wheels 53A and 53B from the encoders 55A and 55B, the rotation angle (steering / turning angle) of the drive unit 23 can be specified. . When the rotation angle (steering / turning angle) of the drive unit 23 reaches 45 °, the control unit 49 stops the forward / reverse rotation of the pair of main drive wheels 53A and 53B as shown in FIG. 10d. Thereby, only the drive unit 23 can rotate and change the direction of 45 ° while maintaining the posture of the carriage 21 from the beginning. Then, after the turning brake 43 is turned on and the drive unit 23 and the carriage 21 are restrained so as not to turn, the pair of main drive wheels 53A and 53B are rotated forward, so that the attitude of the carriage 21 is changed as shown in FIG. The skew of the vehicle main body 20 is started while keeping it.

In this embodiment, the vehicle main body 20 includes a carriage 21, a drive unit 23 connected to the carriage 21 so as to be relatively rotatable, and a turning brake 43 capable of restraining the drive unit 23 and the carriage 21 so as not to be relatively rotatable. The unit 23 is provided with a pair of main drive wheels 53A and 53B that can be independently driven and rotated in the forward and reverse directions, release the turning brake 43, and rotate the pair of main drive wheels 53A and 53B in the forward and reverse directions. Since it is configured to be able to turn, the transport vehicle 10 can travel along a rectangular wave or trapezoidal wave path while maintaining the direction of the carriage 21.
Therefore, a complicated route can be taken even in a narrow place, and the layout flexibility of the production system is improved. Further, since the direction of the carriage 21 is maintained during steering, no rotation moment is applied to the workpiece W, and the conveyance can be speeded up.

  In the present embodiment, the rotation axis L of the auxiliary drive wheel 61 is present in the vertical plane M rising from the ground contact points SA and SB of the pair of main drive wheels 53A and 53B. Also in the operation, the direction of the auxiliary drive wheel 61 is directed to the tangent line of its own steering locus, and the frictional force F received by the auxiliary drive wheel 61 from the ground does not include the component f2 in the rotation axis direction of the auxiliary drive wheel 61. Therefore, even in the above-described traverse operation and skew operation, the auxiliary drive wheel 61 can be prevented from being dragged without the auxiliary drive wheel 61 having a complicated swing structure or the like, so that smooth steering is possible.

FIG. 11 shows another embodiment.
FIG. 11 is a diagram showing the concept. The same parts as those in FIGS. In this embodiment, in addition to the configuration of the above-described embodiment, an actuator (hereinafter referred to as a stepping motor) 91 for rotating the carriage 21 relative to the drive unit 23 is provided.
The stepping motor 91 is fixed to the carriage 21, and the rotating shaft 93 of the stepping motor 91 is fixed to the drive unit 23.
FIG. 12 is a view corresponding to FIG. 2, and according to this embodiment, the guide 81 is unnecessary when compared with FIG.

For example, referring to FIG. 12, when the transport vehicle 10 traveling from the upstream to the downstream of the second line 200 reaches the dent line 200A, the transport vehicle 10 is moved to a predetermined position as shown in FIGS. 13a and 13b. Stop at. The guide 81 is not necessary at this position.
Next, the control unit 49 turns off the turning brake 43 and activates the pair of main drive wheels 53A and 53B to rotate forward and backward as shown in FIG. 13c. Here, even if the turning brake 43 is turned off, the rotation shaft 93 of the stepping motor 91 is fixed to the drive unit 23, so that no relative rotation occurs between the drive unit 23 and the carriage 21.

  At this time, since the control unit 49 acquires the rotation angle measurement values around the drive shafts of the main drive wheels 53A and 53B from the encoders 55A and 55B, the rotation angle (steering angle) of the drive unit 23 can be specified. In this embodiment, when the pair of main drive wheels 53A and 53B rotate forward and backward and the drive unit 23 starts rotating as shown in FIG. 13d, the encoders 55A and 55B sequentially acquire the respective rotation angles. The rotation angle is sequentially input to the control unit 49. The controller 49 sequentially reverses the stepping motor 91 by the amount of rotation of the drive unit 23 based on the acquired rotation angle, thereby maintaining the initial posture of the carriage 21 as shown in FIG. 13e. In this state, the drive unit 23 is steered / turned by 90 °, and the traversing of the transport vehicle 10 is started as shown in FIG. 13f. In this embodiment, the transport vehicle 10 can be traversed without providing the guide 81.

  In the above embodiment, the pair of main drive wheels 53A and 53B are rotated forward and backward to steer / turn the drive unit 23, and at the same time, the stepping motor 91 is rotated reversely to keep the carriage 21 always in the starting position. However, it is not limited to this. As another form, for example, the turning brake 43 is turned on, the pair of main drive wheels 53A and 53B are rotated forward and backward, and the transport vehicle 10 is integrally turned 90 °, and then sequentially input to the control unit 49. Based on the rotation angle of the drive unit 23, it is possible to reversely rotate the stepping motor 91 at a time by 90 ° of the rotation of the drive unit 23 to return the carriage 21 to the original posture.

In addition, embodiment mentioned above shows the one aspect | mode of this invention to the last, and a deformation | transformation and application are arbitrarily possible within the scope of the present invention.
In the above-described embodiment, an example of the work station S that does not require personnel on the production line is shown, but it may be a work station that requires only workers or personnel composed of workers and work robots. In this case, the worker's walking can be reduced and the work can be made more efficient.

DESCRIPTION OF SYMBOLS 10 Carrier vehicle 20 Vehicle main body 21 Carriage 23 Drive unit 41 Rotating shaft 43 Rotating brake 45 Main power unit 47 Auxiliary power unit 49 Control unit 53A, 53B Main drive wheel 55A, 55B Encoder 60 Energy storage mechanism 61 Auxiliary drive wheel 81 Guide Corpse)
SA, SB Grounding point of the main driving wheel SC Grounding point of the auxiliary driving wheel L Rotation axis of the auxiliary driving wheel M Vertical surface rising from each grounding point of the main driving wheel

Claims (5)

The vehicle body includes a pair of independently driven wheels,
The vehicle body can be steered by the difference in rotational speed between the pair of drive wheels,
An energy storage mechanism including an elastic body capable of outputting the stored power by converting the input power into an elastic force, and storing the stored elastic force as power,
An auxiliary drive wheel driven by the power of the energy storage mechanism,
A vehicle characterized in that the rotation axis of the auxiliary drive wheel is present in a vertical plane rising from each grounding point of the pair of drive wheels. The vehicle body has a pair of drive wheels that can be independently driven and rotated forward and backward,
The vehicle body is configured to be steerable by the rotational speed difference and / or forward / reverse rotation control of the pair of drive wheels,
An energy storage mechanism including an elastic body capable of outputting the stored power by converting the input power into an elastic force, and storing the stored elastic force as power,
An auxiliary drive wheel driven by the power of the energy storage mechanism,
A vehicle characterized in that the rotation axis of the auxiliary drive wheel is present in a vertical plane rising from each grounding point of the pair of drive wheels.   The vehicle according to claim 1 or 2, wherein the vehicle body includes a plurality of casters so as to surround each drive wheel and auxiliary drive wheel. The vehicle body includes a carriage, a drive unit coupled to the carriage so as to be relatively rotatable, and a turning brake capable of restraining the drive unit and the carriage to be relatively unrotatable,
The drive unit has a pair of drive wheels that can be independently driven and rotated forward and backward,
The vehicle body is configured to be steerable by the rotational speed difference and / or forward / reverse rotation control of the pair of drive wheels, the turning brake is released, one drive wheel is rotated forward, and the other drive wheel is rotated backward. So that the drive unit can be swiveled,
An energy storage mechanism including an elastic body capable of outputting the stored power by converting the input power into an elastic force, and storing the stored elastic force as power,
An auxiliary drive wheel driven by the power of the energy storage mechanism,
Auxiliary drive wheels are placed in the drive unit,
A vehicle characterized in that the rotation axis of the auxiliary drive wheel is present in a vertical plane rising from each grounding point of the pair of drive wheels.   The vehicle according to claim 4, wherein the carriage includes a plurality of casters.

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